The invention relates to a container composed of paper or paper-like material, having a sleeve and having a bottom and/or a cover, wherein the bottom and/or cover and the sleeve are connected in substantially liquid-tight fashion in the region of a bottom skirt and/or cover skirt respectively, wherein the sleeve is composed of a sheetlike blank, and wherein regions adjoining a first side edge and adjoining a second side edge, situated opposite the first side edge, of the blank are laid one on top of the other so as to form an overlapping side seam and connected to one another by material-bonding engagement.
With the invention, it is sought to improve a container, and a method for producing a container, in particular with regard to the sealing action of the overlapping side seam.
According to the invention, for this purpose, a container having the features of claim 1 and a method for producing a container having the features of claim 12 are provided. The subclaims specify advantageous embodiments of the invention.
In the case of a container according to the invention composed of paper or paper-like material, having a sleeve and having a bottom and/or a cover, the bottom and the sleeve are connected in substantially liquid-tight fashion in the region of a bottom skirt, and the cover and the sleeve are connected in substantially liquid-tight fashion in the region of a cover skirt. The sleeve is composed of a sheetlike blank, and regions adjoining a first side edge and adjoining a second side edge, situated opposite the first side edge, of the blank are laid one on top of the other so as to form an overlapping side seam and connected to one another by material-bonding engagement, e.g. cohesively connected. At least in the region of the bottom skirt and/or of the cover skirt, at least the region adjoining the first side edge forms a step which is offset relative to the rest of the blank.
Through the provision of an offset step in the region adjoining the first side edge, the offset formed by the overlapping side seam can be reduced in terms of its height, possibly even entirely levelled on one side. This facilitates the formation of the bottom skirt and of the cover skirt, respectively, in the region of the overlapping side seam, and in particular the liquid-tight form of the bottom skirt and of the cover skirt, respectively, in the region of the overlapping side seam. The step is advantageously formed, or the sleeve is advantageously produced from the sheetlike blank, such that the offset at the overlapping side seam is reduced in height, or entirely levelled, on the inner side of the sleeve. In this way, it is then possible, in the region of the bottom collar, for the encircling collar of the bottom and, in the region of the cover skirt, for the encircling collar of the cover, to be connected reliably and in liquid-tight fashion to the sleeve, specifically also in the region of the overlapping side seam, because there, there is merely a offset of reduced height, or even no longer an offset at all. In the context of the invention, the same design may be provided in the region of a cover skirt. If appropriate, it may be expedient for the offset step to be formed over the entire length of the side edge. In any case, the sleeve is formed from paper or paper-like material, which may be coated. The bottom and/or the cover may be composed of paper or paper-like material, which is possibly coated, or else from other materials, for example aluminium.
In an embodiment of the invention, the step has an offset and a step surface which extends from the offset to the first side edge, wherein the region adjoining the second side edge lies on the step surface, and the second side edge bears against the offset.
A further problem in the production of a container from a sleeve with an overlapping side seam consists in that, in the case of conventional containers, the face side of the inner side edge comes into contact with the liquid during the filling of the cup. In the case of cups composed of coated paper, the cut edge forming the face side is inevitably not coated unless additional measures are implemented in order to also coat the face side of the side edge. In general, this can be tolerated in the case of paper cups, because paper cups are indeed generally used only once. There are however by all means situations in which the ingress of liquid via the face side of the inner side edge is disruptive, and poses a risk to the sealing action of the overlapping side seam. This may be the case specifically with hot beverages, for example. By virtue of the fact that, now, the region adjoining the second side edge lies on the step surface and the second side edge lies against the offset, the face side of the second side edge can be sealed off, because it now bears against the offset of the step. The face side of the second side edge thus no longer lies unprotected in the interior space of the container. During the connection by material-bonding engagement of the region adjoining the second side edge to the step surface, it is for example possible for a greater amount of adhesive to be applied in the region of the offset of the step in order to close off or seal off the face side of the second side edge in liquid-tight fashion. The second side edge expediently lies on the inner side of the sleeve, such that the region adjoining the second side edge comes into contact with the liquid during the filling of the container.
In an embodiment of the invention, a sealing strip is laid around the second side edge, which sealing strip is connected by material-bonding engagement to the sheetlike blank.
In this way, the face surface of the second side edge can be reliably sealed off against an ingress of liquid.
In an embodiment of the invention, the second side edge is covered, toward the interior space of the container, with a sealing strip which is connected by material-bonding engagement to the inner side of the container.
For example, after production of the overlapping side seam on the sleeve, a sealing strip is applied to the inner side of the sleeve, which sealing strip then covers the gap that may possibly still be present between the face surface of the second side edge and the offset of the step in the region of the first side edge. In this way, the overlapping side seam can be completely sealed off toward the inner side of the sleeve.
In an embodiment of the invention, the region adjoining the second side edge is folded over through 180°, such that a section with two material layers lying one on top of the other is formed, which section forms a new side edge of the blank.
Normally, paper or paper-like material used for producing containers is coated at least on one side, such that liquid is prevented from ingressing into the paper or paper-like material. Often, the coating is applied only on one side not for cost reasons alone. This is the case inter alia also because it is generally sought to apply a print to the outer side, which does not come into contact with liquid, of the sleeve. Here, a coating would merely be a hindrance. By virtue of the fact that, now, the region adjoining the second side edge is folded over through 180°, a new side edge of the blank is formed, at which the coating is then likewise provided. If said new side edge of the blank is now, during the formation of the overlapping side seam of the sleeve, arranged on the inner side of the sleeve, said new side edge is reliably protected, by the coating, against the ingress of liquid.
In an embodiment of the invention, the material thickness of the region adjoining the second side edge is reduced in relation to the rest of the blank.
In the case of the region adjoining the second side simply being folded over through 180°, a region of twice the material thickness in relation to the rest of the blank is realized. This effect can be lessened by reducing the material thickness of the region adjoining the second side edge in relation to the rest of the blank. For example, the region adjoining the second side edge may be milled down to the reduced material thickness. Specifically in the case of paper or paper-like material, the milling of a sheetlike blank in the region of the side edge is possible in a simple manner which is reliable in terms of a process.
A thickness of the section with two material layers lying one on top of the other advantageously corresponds to a material thickness of the rest of the blank.
In this way, a constant material thickness of the sheetlike blank is realized, and at the same time, by virtue of the region adjoining the second side edge being folded over through 180°, a new side edge of the blank can be provided, at which a coating is then provided.
In an embodiment of the invention, the region adjoining the second side edge forms an offset second step, wherein the two steps on the finished container extend in different directions as viewed in a radial direction.
Through the provision of a step both at the region adjoining the first side edge and at the region adjoining the second side edge, it is possible, both on the inner side and on the outer side of the sleeve, to realize an offset with reduced height in the region of the overlapping side seam. For example, on the inner side of the sleeve, an offset height is set which makes it possible to realize a reliable and liquid-tight connection of the sleeve to the bottom in the region of the bottom skirt and/or to the cover in the region of the cover skirt. On the outer side of the sleeve, a height of the offset is set which ensures an aesthetic appearance of the cup and which is for example also comfortable for a user from a haptic aspect.
In an embodiment of the invention, the first and the second step have in each case one offset and one step surface which extends from the offset to the first side edge, wherein a height of the offset of the first and of the second step corresponds in each case to half of the material thickness of the blank.
In this way, both on the inner side of the sleeve and on the outer side of the sleeve, in the region of the overlapping side seam, in each case one offset can be provided which has merely the height of half of the material thickness of the blank.
In an embodiment of the invention, the step has an offset at the transition from the step to the rest of the blank, wherein a height of the step corresponds to the material thickness of the paper or of the paper-like material.
In the case of such an embodiment of the step in the region of the first side edge, it is possible on one side of the blank, expediently on the inner side of the sleeve, for the region of the overlapping side seam to be formed without an offset. As has already been stated, this firstly permits the reliable liquid-tight formation of the bottom skirt and/or cover skirt at which the bottom and/or cover is connected in liquid-tight fashion to the sleeve, and simultaneously permits the sealing of the face side of the second side edge with respect to liquid in the interior of the container.
In a method according to the invention for producing a container, the following steps are provided: forming a step, which is offset relative to the rest of the blank, at a region adjoining the first side edge, placing a region adjoining the second side edge onto a step surface of the step and placing the second side edge against an offset of the step.
In this way, on an inner side of the sleeve, the region of the overlapping side seam can be formed without an offset. By virtue of the second side edge being placed against an offset of the step, the face surface of the second side edge can be at least partially sealed off.
In an embodiment of the invention, the stamping of the step is performed by way of a punch.
Alternatively, the stamping of the step may be performed by way of a roller.
In an embodiment of the invention, the following steps are provided: milling a region adjoining the second side edge of the blank to a reduced material thickness, and folding over the region adjoining the second side edge through 180°, such that a section with two material layers of in each case reduced material thickness lying one on top of the other is formed, which section forms a new side edge of the blank.
In this way, it can be achieved that the new side edge of the blank is equipped with a coating and is thereby protected against an ingress of liquid. Furthermore, it is achieved that the folded-over region does not have twice the material thickness of the blank, but rather has merely a reduced material thickness in relation thereto, ideally the same material thickness as the rest of the blank. For this purpose, it is then necessary for the region adjoining the second side edge of the blank to be milled to half of the material thickness.
Further features and advantages of the invention will emerge from the claims and from the following description of preferred embodiments of the invention in conjunction with the drawings. Here, individual features of the various embodiments illustrated in the drawings and described may be combined with one another in any desired manner without departing from the scope of the invention. In the drawings: